Rotary valve engine



May 2, 1939. E. G. BAKER 2,156,749

` ROTARY VALVE ENGINE Filed April .4, 1936 i Patented May 42,4 1939UNITED STATES PATENT o1=1=1cE 2,156,749 ROTARY VALVE ENGINE Erwin G.Baker, Indianapolis, Ind. Application Api-ii 4, 1936-, serial No. 72,7154 claims'. (01423-190) This invention relates to internal combustionengines of the rotaryvalve type, and has for its broad object -theproduction of such an engine which will be an improvement over priorrotary- 5 valve engines. More specically, it is my object to produce arotary valve which will not .deteriorate rapidly under the conditions ofwear and high temperature to which it is subjected in use. Anotherobject of my invention is to provide an improved means for Vholding thevalve against its seat under explosion pressures and thereby to reduceleakage and increase efficiency. Still another object of my invention isto provide a novel means of lubricating the valve.

In carrying out my object, I form the roller of carbon, preferablycarbon of the type used as electrodesin electric furnacesand Ithoroughly impregnate this carbon with oil. I find that a valve ofcarbon so treated is exceptionally re- 20 sistant to wear and to theaction of hot gases.

The valve is suitably mounted for rotation in floating bearings forcedtoward the cylinder or cylinders to hold the valve in engagement there-With by means of liquid-filled vessels with resil- -H5 ient walls, thepressure within which may be maintained sumciently great to keep thevalve seated at all times. To lubricate the valve, I provide a conduitextending from above the oil level in the engine crankcase to the top ofthe valve, such conduit serving to convey oil in the form of mist fromthe crankcase to the valve.

The accompanying drawing illustrates my invention: Fig. l is a sideelevation of a four-cylinder engine to which my invention has beenapplied, parts of the engine being broken away to illustrate moreclearly the interior construction; ,and Figs. 2, 3, and 4 are transversevertical sections on the lines 2-2, 3 3, and 4-4 of Fig. l.

The four-cylinder engine shown in the drawing' of the conventional type,including a crankcase" Itl, a cylinder block II, and pistons` I2. Thehead I3, which may contain combustion chambers and spark plugs, issecured in any convenient manner to the top of the block II and has acentral longitudinal bore for the reception of the rotary 5 Valve It.The cylinder block II and head I3 may GFI cylinder head there isdisposed a generally semicircular hollow vessel 2l)` the inner surfaceof which is curved to t the outer face of the bearing I8 and the outersurface of which bears against the top portion of the recess wall, as isclear from Fig. 2. The vertical walls of the Vessels 20 are shaped to benon-planar, as by being made concave, in the manner illustrated inFig. 1. Such side walls permit relative radial movement between theinner and outer arcuate walls of the vessel.

The vessels 20 are connected with some suitable source of iluid underpressure. Preferably this source is a pump 22 driven by the engine andhaving anoutlet connected through apipe 23 to the vessels 20. Thevessels 20 and the bearings I8 may be protected by cover plates 2l whichare secured against the ends of the head I3 and through each of whichthe associated pipe23 and shaft l1 extend. The openings in the covers 2|which pass the branch of the pipe 23 and the shafts I1 are of suflcientvertical extent to permit a slight degree of vertical movement of thepipe branches and shafts.

Preferably, oil is used as the fluid in the vessels 20, and a portion ofthe oil discharged fromv the pump 22 may be used for lubricating themoving parts in the head. To this end, the pipe 23 may be provided witha branch 24 having a valve 25 and discharging into one of the recessesat the ends of the head. The two recesses are interconnected by passages26 which extend longitudinally through the head on each side but wellbelow the axis of the valve i 6. An overflow pipe il connected with oneof the recesses maintains the oil level in both substantially constant,the

inlet for the overflow pipe 2T being high enough so that the lowerportion of each ofthe bearings I8 is immersed in the oil.

At points along its length. each of the passages 26 is provided withinwardly directed openings 30 communicating with oil-containing recesses3| in the wall of the valve-receiving bore of the cylinder head. 'I'heserecesses are located between the" cylinder ports and extendcircumferentially for a considerable distance in each direction from thebottom of the valve. Additional lubrication crease the effectiveness ofthe seal by insuring that the valve-.will contact the bore-surface atpoints close to the cylinder ports. The flexibility for the valve may beprovided by a conduit 35 which extends upwardly from the crankcase i tocommunicate with a passage 36 formed `in the head I3 above the valve.The passage 36 is provided at intervals along its length with openings31 communicating with recesses 38 generally similar tothe recesses 3| inthe bottom surface of the head bore. In the operation of the engine, anoil mist will form in the crank-case, and a portion of this mist will beconveyed through the conduit 35 and passage 36 to the recesses 38.

For each of thecylinders, the head is provided *with a cylinder port 40,an inlet port 4|, and an exhaust port 42. It is to be understood ofcourse that the exhaust ports and inlet ports will be connected tosuitable manifolds, although such manifolds are not shown in thedrawing. The ports 40, 4|, and 42 are all located in the same planetransverse tothe valve axis, and in this plane the valve is providedwith a circumferentially extending passage 43 by means of whichcommunication of the cylinder port with the exhaust and inlet ports iscontrolled. Each of the passages 43 is formed with rounded ends andsmoothly curved sides so as to reduce to a substantial-minimum theresistance which it offers to the flow of gas. I find that in order toobtain ports 40, 4|, and 42 large enough to avoid undue restrictions ofthe gases flowing through them and in `order to obtain valve passages 43of adequate cross-sectional area and length it is desirable to employ avalve of a diameter materially larger than that of the cylinder.

I find that with the valve arrangement illustrated in the drawing I candepart with advantage from the conventional valve-timing used ininternal combustion engines of the automobile type. Thus, I can deferthe exhaust opening until near the end of the explosion stroke, or evento a point beyond the end of the explosion stroke;

and, in addition, I can have a substantial degree of overlap between theopening of the inlet valve and the closing of the exhaust valve.

In the engine shown in the drawing, it is intended that the valve IBwill operate at half crank-shaft speed so that it will make one completerevolution for each cycle of engine operation. My invention is not to beunderstood as limited to this arrangement, however, as I could, forexample, operate the valve at one-quarter crank-shaft speed and providetwo of the passages 43 for each of the cylinders.

In the operation of the engine described. the rotation of the valveserves to control in proper manner the connection of each cylinder withits associated inlet and exhaust ports. During engine operation, the oiltransmitted under pressure by the -pump 22 through the pipe 23 to thevessels' 20 serves to exert, through the bearings I8, a considerabledownward pressure upon the shaft Il and the valve I6, thus acting tohold the valve firmly in contact with its seat. In this connection, Ifind that the oil-containing recesses 3|, by reducingP the-bearing areabetween the valve and the bore in which it is disposed, serve to inofthe side walls of the vessels 2liy permit such radial expansion of thosevessels as is necessary to permit them to exert the desired downwardforce upon the bearings IB. By adjusting the valve 24, the pressuremaintained within the vessel and the force with which the valve I8 isseated, may be varied as desired.

As indicated above, I ind'carbon of the type lused in electric-furnaceelectrodes to be a highly suitable material for the valve i6. Thewearing qualities of this material can be increased manyfold if it isfirst impregnated with-lubricating oil. To secure this impregnation, Iimmerse the valve in4 oil and maintain it therein until it is thoroughlysaturated, the point of saturation being determined by repeatedWeighings of the valve. The oil used is preferably an oil of relativelyhigh flash point-say in the neighborhood of 700 F. The impregnation ofthe carbon valve is desirably carried out at elevated temperature and ata pressure in the neighborhood of 500 pounds per square inch. Underthese conditions the carbon valve will absorb oil up to about 30 percentof its weight.

I claim as my invention:

l. In an internal combustion engine, a cylinder, a rotary valve, acylinder-head provided with a bore for the reception of said valve andwith a cylinder port providing communication between said bore and thecylinder, and means responsive to iluid pressure for forcing said valveinto contact with the wall of said bore adjacent said port, said meanscomprising a closed flexible-walled liquid container, and means forsupplying liquid Yunder pressure to said container.

2. In an internal combustion engine, a cylinder, a rotary valve, acylinder-head provided with a bore for the reception of said valve andwith a cylinder port providing communication between said bore and thecylinder, and means responsive to iluid pressure for forcing said valveinto contact with the wall of said bore adjacent said port, said meanscomprising two closed ilexible-walled containers spaced apart axially ofsaid valve and disposed on opposite sides of said cylinder, and meansfor supplying liquid under pressure to said container.

3. In an internal combustion engine, a cylinder, a`cylinder-head, arotary valve, said cylinwhereby the force exerted on said valve by saidfluid-pressure' responsive means will vary with engine speed.

4. 'Ihe invention set forth in claim 3 with the addition of means forlimiting to a predetermined maximum the unit pressure of fluid suppliedto said fluid-pressure responsive means.

ERWIN G. BAKER.

